Managing one lamb, two lambs or more at scanning time

One of them is meeting the feed requirements of each group of ewes, along with the second component being mob size.

Brendan Robertson, Robertson Pregnancy Scanning, Mangoplah, near Wagga Wagga, said he is starting to see some operations manage ewe groups even as far as splitting them into ewes scanned into triplets, as well as twins and singles.

He said there are some breeds that do produce more triplets such as Composites and Multimeats.

Mr Roberston said although the last few seasons have been good, he has found a lot of ewes that have been affected by the wet country and sore feet have had trouble joining this year.

"I've been scanning since the middle of December, people that have lots of dries have been mobs of sheep with sore feet," Mr Robertson said.

"Even around Hillston where they normally don't have any troubles with sore feet."

Sheep production adviser, Anthony Shepherd, Sheepmatters, Cootamundra, said the amount of producers now up taking pregnancy scanning ewes in the industry has increased significantly, with the exercise increasing since the earlier droughts in 2018 and 2019.

"A lot of producers know there is benefit in separating twins from singles and also identifying dry ewes which are cost to production," Mr Shepherd said.

"Pregnancy scanning is not about identifying dries, that's just one part of it.

"It is about managing different pregnancy status, the singles, twins and triplets and meeting their huge difference in energy requirements through lambing but also up to lambing."

"In regards to what digestible pasture they are run on."

Mr Shepherd said that single bearing ewe does not need to be on a high performance pasture, developing the fetus' in the last five weeks, compared to a twin or a triplet.

"Lets just say both the ewes are dry, a 65 kilogram ewe, they will need nine megajoules of energy," Mr Shepherd said.

"Then one ewe gets pregnant with single and one gets pregnant to twins, they got from that point of needing nine megajoules of metaboliable energy (ME), then turn into everyday at lactation needing 18.5 ME.

"But the twin ewe at 65 kg will need 26.5 ME at lactation."

"As a reference, one kilogram of barley will give you 10.8 ME everyday."

Mr Shepherd said after pregnancy scanning he condition scores ewes, with the ideal condition score for the ewe would be between three to 3.4 and any ewes that are under a 2.7 condition score, those ewes will be separated and go onto a different diet.

"Anything under 2.7 condition score especially in a twin bearing ewe and above four year old you get a high susceptibility of pregnancy toxcemia," Mr Shepherd said.

"The less condition is there the less energy that you will have so when it comes to that higher requirement of energy of lactation.

"If it's not been replaced and she will run out of energy and that's that's a precursor for pregnancy toxemia."

One of the biggest drivers of lamb survivaliblty being body weight at birth, which can also be managed when scanning and separating singles and multiples.

Mr Shepherd said in the second trimester of pregnancy, between day 50 and 100 is when the placenta is developed, which then feeds the fetus or fetus' in the last trimester of the pregnancy.

"If you were to not to feed the placenta, on the twin bearing ewes on a high digestible pasture, you will have a smaller fetus with twins," Mr Shepard said.

"When they drop below a body weight of three and a half kilograms, there will be an increase in lamb mortality of 15 per cent.

"The smaller surface area the skin of the lamb the quicker the body temperature will drop."

Mr Shepherd said the smaller lambs will use up an energy reserve called brown fat, which keeps the lambs going until they get the suck of colostrum, whereas the larger lambs are able to maintain their body weight better.

He said another part if people are not aware of the placenta development is putting old single bearing ewes on highly digestable pastures and then having trouble with larger lambs when it comes time for them to be born.

"If you were old ewes that were scanned in single, being plus five year olds, if you were put them onto a high digestible pasture such as legume like clovers or lucerne which have a higher protein and highly digestible, you will awesome at building the placenta, but what happens is on the flip side of having to small of a lamb, you will have a really big single lamb and that is dystocia," Mr Shepherd said.

"You will have stuck lambs in ewes that don't have energy to push them out."

Mr Shepherd said he suggests for producers to manage triplet bearing ewes in mobs of 18 to 25 head in a 6 hectare paddock, with twins then being put into mobs of 65 in a 10 hectare paddock, which he puts to practice in his own Merino flock.

Ganmain sheep producer Hugh Cruikshank, runs 1700 first cross ewes and 1000 Pastora blood Merino ewes, along with a mixed cropping program throughout the operation.

The Merino ewes are joined to a Highlander ram to produce first cross ewes for the crossbred lamb program, with all ewes being joined for six weeks.

"I just manage the ewes in twins, singles and dry," Mr Cruikshank said.

"Once they are in that they stay in that for 12 months until they come back for scanning next year.

"Wer'e doing this with our ewe lambs at seven months of age, they joined up at 63pc last year."

Mr Cruikshank said there are a number of grazing crops planted for the ewes, with a large portion of vetch, turnip and radish in the mix to provide high quality feed for them, with the multiples and Merinos being prioritised for the better crops for energy requirements and wool growth.

"Twins need more feed and singles need a lot less feed, so if you're tight you can run your singles in tighter paddocks," Mr Cruikshank said.

"As they need less feed because in the third trimester you don't want bigger ewes so you can manage the feed that way with your groups."